Generally, a plasma etching process and a plasma CVD process have been widely employed in a manufacturing steps of a semiconductor device such as a DRAM and a micro processor. The number of particles adhered to a sample to be processed such as a wafer is required to be reduced as one of problems to be solved in processing of the semiconductor device using plasma. For example, when the particle drops on the fine pattern of the sample to be processed during the etching or prior to the processing, etching to the dropped part is partially inhibited, thus causing the defect on the fine pattern of the sample to be processed such as disconnection, resulting in reduced yielding. In the turbo-molecular pump, the blades rotate at the rotating speed of 300 m/s, for example, to scatter the particle is considered as one of the factors to cause the particle dispersion into the vacuum chamber. Meanwhile, the particle flows into the turbo-molecular pump at several m/s as the flow rate of gas. As the particles apparently drop at the considerably low speeds with respect to the rotation blade, most of the particles fail to pass through the rotation blades, and impinge against the leading end of the rotary blade and are reflected at the high speed to be dispersed into the chamber.
Japanese Patent Application Laid-Open Publication No. H8-14188 discloses that the stationary blade for preventing reflection of the foreign substance is disposed at one stage upper position with respect to the rotary blade. Japanese Patent Application Laid-Open Publication No. 4-284840 discloses that the baffle plate (plate for reflecting foreign substance) is disposed above the turbo-molecular pump. Japanese Patent Application Laid-Open Publication No. 2008-240701 discloses that plural baffle plates are disposed above the turbo-molecular pump. Japanese Patent Application Laid-Open Publication No. 2006-216710 discloses that the baffle plate is disposed on the side surface of the sample stage on which the sample to be processed is placed inside the vacuum processing chamber so as to prevent the dispersed particle from reaching the space for processing the sample.
Meanwhile, Japanese Patent Application Laid-Open Publication No. 2006-41088 discloses the processing gas supply system for supplying the processing gas into the vacuum processing chamber in detail.